Extension beam drafting instrument



Jan; 8, 1952 J. F. JOY

EXTENSION BEAM DRAFTLNG INSTRUMENT Filed March 24, 1947 WIN PatentedJan. 8, 1952 EXTENSION BEAM DRAFTIN G INSTRUMENT Joseph F. Joy,Pittsburgh, Pa., assigner to Joy Manufacturing Company, Pittsburgh, Pa.,a corporation of Pennsylvania Application March 24, 1947, Serial No.736,825

4c Claims. (Cl. 33--158) This invention relates to drawing instrumentsand more particularly to an improved extension beam compass of arelatively simple construction having a wide range of adjustment,thereby increasing the usefulness of the instrument.

In the extension beam Compasses of known designs, there are usuallyprovided telescopically arranged, relatively slidable beam sections, onesection having a point holder carried at its outer extremity and theother section having slidable` thereon and adjustable relative thereto aholder for a drawing element or divider needle. By sliding the holder ofthe drawing element or divider needle along itsv beam section, it may bebrought relatively close to the point holder, and by fully extending thebeam sections and sliding the drawing element or divider needle holderto the outer extremity of its beam section, the holders may be widelyspaced. ln one known construction, the telescopically arranged beamsections are separable, and when it is desired to obtain a wideadjustment of the pointers or drawing elements, it is necessary toremove one beam section, turn it end for end, and reinsert it in itsreversed position on the other beam section. The present inventioncontemplates an improvement over known types of beam compasses in thatthe -te-lescopically arranged, relatively slidable beam sections havepermanently secured to their opposite extremities holders for the pointand drawing element or divider needle so that independent slidableadjustment of one holder along its beam section together with thespecial adjusting and setting means therefor, are avoided and adjustmentof the pointers between zero and maximum positions areeffecte'd simplyby relatively extending the beam sections. Accordingly, the

structure of the present invention is simplified,

and special sliding holders and their adjusting and setting means andthe necessity of taking the beam sections apart are completelyelimihated.

It is an object of the present invention to provide an improved drawinginstrument having an increased range of usefulness. Another object is toprovide an improved extension beam compass having improved. structuralfeatures whereby simplicity and ease of adjustment are' attained. Afurther object is to provide an improved. extension. beam compass havingtelescopically arranged, relatively slidable beam sections, each sectionhaving a holder permanently secured thereto at its outer end and soarranged and constructed that the holders may be brought close ingentesor moved wide apart simply by adjusting the beam sections. Yetanotherbbject is to provide an improved extension beam compass havingimproved telescopic beam sections whereby the ends of the beam sections,which are most remote when the beam sections are fully extended, may bebrought relatively close together When the beam sections are in theireX- treme opposite adjusted position. A still further object is toprovide an improved extension beam compass comprising telescopicallyarranged, relatively slidable beam sections of an improved designwhereby the ends of the beam sections, which are most remote when thebeam sections are in maximum extended position, carry holders for thepoint and drawing or divider needle elements, and so arranged andconstructed that the remote ends, upon telescoping of the sections, maybe located so that the holders are brought together in abutting relationwith the point and drawing or divider needle elements at zero position.Yet another object is to provide an improved extension beam compasswhich, by a simple sliding movement, may be readily adjusted from zeroposition to its maximum extended position. Other objects and advantagesof the invention will, however, hereinafter more fully appear.

In the accompanying drawing there is shown for purposes of illustrationone form which the invention may assume in practice.

In this dra-Wing:

Fig. 1 is -a top plan View of a beam compass constructed in accordancewith an illustrative embodiment of the invention, with the beam sectionsfully extended to locate the holders wide apart.

Fig. 2 is a side elevational view of the beam compass shown in Fig. l.

Figs. 3 and 4 are, respectively, top plan and side elevational views ofthe compass shown in Figs. 1 and 2, with the beam sections in theirextreme opposite telescoped position to locate the holders closetogether.

Fig. 5 is an enlarged longitudinal vertical sectional view taken on line5-5 of Fig. l.

Figs. 6 and '7 are cross-sectional views taken on lines 6--6 and 1--1 ofFig. 5.

Fig. 8 is a vertical sectional View taken on line 8-8 of Fig. 2.

Fig. 9 is an enlarged cross-sectional Viewv taken on line 9-9 of Fig. 4.

Fig. 10 is a side elevational view showing the beam compass irlyfoldedposition, with the holderpoint and thedawine or divider needle elementEskiued in the art.

pencil, divider needle and trammel points, other readily drawn by but asimple adjustment 'ofi parts. It will be evident that features of theinvention may be embodied in instruments of other types, such as atrammel for'measuring distances in machine shop work.

The improved extension beam compass is generally designated I andcomprises a pair of telescopically arranged, relatively slidable, innerand outer tubular beam sections 2 and 3 having close sliding fitswhereby they may be readily extended Vor adjusted with respect to eachother but with sufficient frictional resistance to retain the sectionsinadjusted positions. The beam sections are preferably of sheet metal andformed by stamping, to obtain light weight, although they -may beconstructed in various other suitable manners. "While the tubular beamsections are shown of generally ovate cross section, it will beunderstood that cross sections of other shapes vmay be employed, ifdesired. Secured in any suitable manner to the remote ends'of the beamsections are holders 4 and 5, and the holder i ,may carry an adjustablepoint or needle 6 while the holder 5 may carry an adjustable pen orpencil holder element I or a divider needle. ously, the relativepositions of these elements to the sections may be reversed. In atrammeLsuch as is used in machine shop work, these holders are known astrammel heads for carrying trammel points, in a manner well known tothose Instead of the point, pen,

known forms of work engaging elements may be employed. The point holder4 preferably has i a sheet metal body portion 8 suitably permanentlysecured to the exterior of the outer beam section 3, and apoint-carrying element 9 is swiveled at I0 on the bodyportion 8and isprovided with a clamp Il which may be tightened by a suitable wing-screwI2. `The holder 5 for the drawing element or divider needle has a bodyportion l* likewise preferably formed of sheet metalr and suitablypermanently secured to the inner beam Asection 2, and has acarrying-element I@ for the pencil, pen or divider needle, swiveledthereon at I5, likewise having a clamp I6 which may be tightened by awing-screw I1. The wing-screws engage non-rotatable nuts, shown at is inFigs.

" 8 and 11, but, if desired, the nuts may be'winged and rotatable andthe screws may be stationary.

`The structures of these holders, including the Yto provide a slotextending longitudinally i. throughout its length, and the body portionI3 of theholder 5 is movable Withinthis slot, as

shown in Figs. 4 and 9, during-certain positions of relative adjustmentof the beam sections. The inner beam section 2 is formed with an opentopproviding a slot 2| extending throughout'a major portion of'its lengthand openingfthrough 'one end thereof,4 land this slot is closed atv itsObvi- 4 other end at 22 as by bending the edges of the beam sectionafter assembly of the sections so that they are close together. Securedto the exterior of the outer beam section 3 at its end opposite from itsend which has the holder 4 secured thereto, is a sheet metal member 23having an open bottom at 24 of the same width as the slot 28 (see Figs.5 and 7). The member 23 has an inwardly bent portion 25 projecting intothe upper slot 2| and engageable with the closed end vZero position asshown. v

The inner beam section 2 is provided on its top surface with parallelseries of graduations, as indicated at 21 and 28, along its oppositesides, in this instance, graduated into inches and fractions thereoffrom one to twenty-four inches. Evidently, these graduations may bemodined and the beam sections ymay be shorter or of greater lengths. Oneseries of graduations on one side of the beam section are numbered fromone to twelve, while the other series of graduations on the other sideof the beam section are numbered from thirteen to twenty-four. Themember 23 is formed with a sight opening 29 having an indicator such asa pointer'30 therein, the latter adapted to travel along one series ofgraduations at one side of the inner beam section, and the body portion8 of the holder 4 has a similar sight opening 3lA having an indicatorsuch as a pointer 32 therein, the latter adapted to travel along theother series of graduations at the other side of the inner beam section.Thus the position of adjustment of the beam compass may be readilydetermined.

yWhen the beam compass is not in use, the beam sections may betelescoped into their coextensive relation shown in Fig. 10, with the Ypoint-carrying element 9 and the drawing ele- Y ment or divider needlecarrying element I4 swung inwardly on their swivels I0 and I5 againstthe Vbottom sides of the beam sections and held there by the swivelclamps.

'As a result of this invention, an improved drawing instrument isprovided having'not only simplicity in construction but also a widerange of adjustment, greatly lending to the usefulness of theinstrument. By telescopically arranging and constructing the beamsections in the manner disclosed, the point and drawing element ordivider needle of the compass may be readily adjusted'from a zeroposition to the maximum extended position by a simple sliding motion andwithout any rearrangement or reversal of parts. By permanently securingthe holders for the point and drawing element or divider needle directlyto the beam sections, the necessity of separate relatively complicatedslides and adjusting and ksecuring devices therefor clearly apparent tothose skilled in the art.

Whilethere is in this application speciiically described one form whichthe invention'inay'assume in practice, it will be understood that thisform of the same is shown for purposes of illustration and that theinvention may be modified and embodied in various other forms withoutdeparting from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In an extension beam drafting instrument, the combination comprisinga pair of cooperating telescopically arranged, relatively axiallyadjustable, flat beam sections, the outer beam section being tubular andhaving a slotlike opening extending along a flat side thereof a majorportion of its length, said beam sections being relatively axiallyadjustable between a position wherein their remote ends are spaced apartnearly the full cumulative length of said sections and a positionwherein said ends are in close proximity, and work holders for draftingelements secured to said ends respectively of said beam sections betweenthe side edges of said beam sections, said holders when in use disposedat substantially right angles to the planes of the iiat sides of saidbeam sections at the side of the instrument toward the work, the flatside surfaces of said beam sections being substantially parallel to thesurface of the Work during normal use of the instrument, the holdersecured to the inner beam section moving in said slotlike opening duringa portion of the relative adjustment of said beam sections, and saiddrafting elements being disposable in zero position when said ends arein close proximity as aforesaid.

2. In an extension beam drafting instrument, the combination comprisinga pair of cooperating telescopically arranged, relatively axiallyadjustable, at beam sections the outer beam section being tubular andhaving a slotlike opening extending along a flat side thereof a majorportion of its length, said beam sections being relatively axiallyadjustable between a position wherein their remote ends are spaced apartnearly the full cumulative length of said sections and a positionwherein said ends are in close proximity, and work holders for draftingelements secured to said ends respectively of said beam sections betweenthe side edges of said beam sections, said holders when in use disposedat substantially right angles to the planes of said fiat sides of saidbeam sections at the side of the instrument toward the work, the flatside surfaces of said beam sections being substantially parallel to thesurface of the Work during normal use of the instrument, the holdersecured to the inner beam section moving in said slotlike opening duringa portion of the relative adjustment of said beam sections, and saiddrafting elements being disposable in zero position when said ends arein close proximity as aforesaid, with said work holders in abuttingrelation.

3. In an extension beam drafting instrument, the combination comprisinga pair of cooperating telescopically arranged relatively axiallyadjustable beam sections, the outer beam section being tubular andhaving a slotlike opening extending along one side thereof a majorportion of its length and the inner beam section also being tubular andhaving a, slotlike opening extending along a major portion of its lengthat the opposite side thereof from the slotlike opening of said outermember, said beam sections being relatively axially adjustable between.a position wherein their remote ends are spaced apart nearly the fullcumulative length of said sections and a position wherein said ends arein close proximity, a stop element on said outer beam section andprojecting into said slotlike opening in said inner beam section forlimiting the maximum adjusted positions of said beam sections, and workholders for drafting elements secured to said ends respectively of saidbeam sections, said holders when in use disposed at substantially rightangles to said beam sections at the side of the instrument toward thework, the holder secured to the inner beam section moving in saidslotlike opening in said outer beam section during a portion of therelative adjustment of said beam sections, said drafting elements beingdisposable in zero position when said ends are in close proximity asaforesaid, and said holders being movable into abutting relation tolimit the extent of collapse of said beam sections.

4.-. In an extension beam drafting instrument, the combinationcomprising a pair of cooperating telescopically arranged relativelyaxially adjustable beam sections, the outer beam section being tubularand having a slotlike opening extending along a major portion of itslength, said beam sections being relatively axially adjustable between aposition wherein their remote ends are spaced apart nearly the fullcumulative length of said sections and a position wherein said ends arein close proximity, and work holders for drafting elements secured tosaid ends respectively of said beam sections, the holder secured to theinner beam section moving in'said slotlike opening during a portion ofthe relative adjustment of said beam sections, and said holders havingpivoted portions disposable when in use in positions at substantiallyright angles to said beam sections at the side of the instrument towardthe work and foldable along the sides of said beam sections when theinstrument is not in use, the ends of said pivoted portions extendinginto said slotlike opening against the adjacent side of the inner beamsection when said holders are in folded relation.

JOSEPH F. JOY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 370,313 Burroughs Sept. 20, 1887695,661 Theibault Mar. 18, 1902 718,923 Ellsworth Jan. 20, 1903 916,912Carrier Mar. 30, 1909 1,134,692 Mason Apr. 6, 1915 1,258,536 Conner yMar. 5, 1918- 1,288,412 Hill Dec. 17, 1918 1,488,482 Eckman Apr. 1, 19241,617,662 Ackroyd Feb. 1.5, 1927 1,670,509 Jung May 22, 1928 2,440,973Podolan May 4. 1948;

